Semiconductor device and a method of manufacturing the same

ABSTRACT

It is an object to provide a semiconductor device integrating various elements without using a semiconductor substrate, and a method of manufacturing the same. According to the present invention, a layer to be separated including an inductor, a capacitor, a resistor element, a TFT element, an embedded wiring and the like, is formed over a substrate, separated from the substrate, and transferred onto a circuit board  100 . An electrical conduction with a wiring pattern  114  provided in the circuit board  100  is made by a wire  112  or a solder  107 , thereby forming a high frequency module or the like.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a TFT, a resistor element, an LCelement attenuating a predetermined frequency band, a semiconductordevice on which an integrated circuit combining these elements ismounted, and a method of manufacturing the same.

Note that a semiconductor device in this specification means generaldevices which can function by using semiconductor characteristics, andall of electro-optic devices, semiconductor circuits and electronicdevices are the semiconductor devices.

2. Description of the Related Art

A high frequency integrated circuit (also referred to as MMIC) in whichan active element such as a transistor and a passive element such as acapacitor, a resistor or an inductor are formed on one semiconductorsubstrate is known. An active element such as a MESFET, a HEMT, or aHBT, and a lumped parameter element such as a capacitor, an inductor, ora resistor, and a distributed parameter element such as a microstripline, or a coplanar line are formed together on a semiconductorsubstrate in an MMIC. Note that a via hole is used for earthing. It issmall and lightweight, and has a good high frequency property, ascompared with one on which an active element and a passive element aremounted individually. Because a semiconductor process generally has ahigh cost, however, when a large area is needed for a passive element,the cost is disadvantageous.

Commonly, a high frequency integrated circuit (MMIC) is configured byintegrating a transistor using a single crystal silicon wafer or atransistor using a compound semiconductor, and a chip type inductor orcapacitor, and further, a filter element such as a SAW element.

Integration and multifunction of mobile communication devices typifiedby an analog cellular phone and a digital cellular phone, a PHS terminaland the like, are made by the development of MMIC.

In addition, an active element and a passive element are formedindividually, and a circuit that they are mounted on the samesemi-insulating substrate is referred to as a HMIC or a HIC.Alternatively, it can be merely referred to as a MIC. An alumina andbarium titanate substrate is used for a circuit board, a GaAsPHEMT isused for the active element, a plate electrode shaped chip capacitor, aninductor using a bonding wire, a TaN thin film resistor are used for alumped parameter element, and a microstrip line is used for adistributed parameter element in the HMIC. Note that a through hole isused for earthing.

In addition, Patent Document 1 describes that a thin film laminationhaving ten layers or less is formed for a thin film integrated circuitin a thin film process in a complex integrated circuit component.Further, Patent Document 2 describes that a high frequency module isformed by compounding a circuit formed with a TFT and a high frequencyfilter.

Patent Document 1

Japanese Patent Laid-Open No. Hei 7-45787

Patent Document 2

Japanese Patent Laid-Open No. Hei 10-209464

BRIEF SUMMARY OF THE INVENTION

A further reduction in size and weight, thinning, lower cost arerequired, and the present invention provides a novel structure that canintegrate various complex circuits.

Means for Solving the Problem

One feature of the present invention is that a circuit (or an element)mounted conventionally as a chip component (L, C, R) is formed on aninsulating substrate without using a semiconductor substrate, andseparated from the insulating substrate by a separation technique, andbonded to a circuit board or a film.

Specifically, one feature of the present invention is that a paste foran internal electrode layer and a paste for a dielectric layer arelaminated by a sheet method or a printing method over a substrate toform and bake a laminated capacitor, a laminated inductor (a laminatedcoil), a resistor circuit, and the like. Thereafter, they are separatedfrom the substrate and transferred to a circuit board or a film.

In addition, one feature of the present invention is that a passivecircuit element (a LPF, a BPF (representatively, a SAW filter), adiplexer, a coupler, a balun or the like) that combines a capacitor, aninductor and a resonator (a distributed constant) is formed on asubstrate, and then, separated from the substrate, and transferred to acircuit board or a film.

In addition, one feature of the present invention is that a capacitorelement using a high dielectric thin film as a capacitive insulatingfilm is formed on the same substrate as a CMOS circuit made up of a TFT,and then, separated from the substrate and transferred to a circuitboard or a film.

In addition, one feature of the present invention is that an impedancematching circuit comprising a distributed constant line such as amicrostrip line or a coplanar line in a high frequency region is formedon a substrate and separated from the substrate, and transferred to acircuit board or a film.

In addition, according to the present invention, an insulating layer isformed on a substrate, an embedded wiring (such as Cu, Au, Ag, Ni,chrome, palladium, rhodium, tin, lead, or an alloy of these elements) isformed, and then, separated from the substrate and transferred to acircuit board or a film to use it as various wirings. In this case, notonly the embedded wiring with low resistance but also the insulatingfilm in the circumference is transferred in a sheet-like shape. Inaddition, after forming an embedded wiring surrounded with a metalprotective film (such as Ti, TiN, Ta, or TaN), it may be separated fromthe substrate and transferred to a circuit board or a film.

In addition, one feature of the present invention is that a plurality ofvarious circuits, elements, and wirings described above are formed onthe same substrate, and then separated from the substrate, andtransferred to a circuit board or a film. Noise can be reduced by thepresent invention by which various circuits, elements, wirings can beformed on the same substrate. According to the present invention, an RFcircuit, a CPU, a memory (SRAM, DRAM, a flash memory) and the like canbe formed on the same substrate, and transferred. Further weight saving,integration or reduction in cost is realized by the present invention.

A structure of the present invention disclosed in this specification isa semiconductor device having a complex integrated circuit where asubstrate on which an inductor is formed on an insulating surfacethereof and a layer including a thin film transistor connected to theinductor are laminated, as shown by an example in FIG. 2(C).

Another structure of the present invention is a semiconductor devicehaving a complex integrated circuit where a substrate on which acapacitor is formed on an insulating surface thereof and a layerincluding a thin film transistor connected to the capacitor arelaminated, as shown by an example in FIG. 2(D).

Another structure of the present invention is a semiconductor devicehaving a complex integrated circuit where a substrate on which aninductor and a capacitor are formed on an insulating surface thereof anda thin film transistor connected to the inductor or the capacitor arelaminated, as shown by an example in FIG. 1 or FIG. 3.

Another structure of the present invention is a semiconductor devicehaving a complex integrated circuit where a substrate on which aninductor, a capacitor, and a resistor element are formed on aninsulating surface thereof and a thin film transistor connected to theinductor, the capacitor, or the resistor element are laminated.

In each of the above described structures, one feature is that theinductor is a laminated inductor or is formed from a spiral liketransmission line. Further, in each of the above described structures,one feature is that the capacitor is a laminated capacitor or a MIM typecapacitor.

Another structure of the present invention is a semiconductor devicehaving a complex integrated circuit where a substrate on which a SAWelement is formed on an insulating surface thereof and a thin filmtransistor connected to the SAW element are laminated, as shown by anexample in FIG. 5.

In each of the above described structures, one feature is that the SAWelement is made by using a diamond thin film.

In each of the above described structures, one feature is that thesubstrate is a ceramic substrate, a quartz substrate, a glass substrate,or a plastics substrate. It can be selected appropriately depending on asubstrate for mounting, thereby enhancing reliability.

In each of the above described structures, one feature is that a CPU, amemory element, a thin film diode, a photoelectric transducer, or aresistor element is provided on the substrate having the insulatingsurface.

In each of the above described structures, the semiconductor device is avideo camera, a digital camera, a goggle type display, a navigationdevice typified by a car navigation, a DVD player, an electronic gamemachine, a card (such as an ID card, a card having a functional circuitor an element, or a card key), a computer, a memory that can memorizedata, or a personal digital assistant.

A separation method and a transfer method are as follows: a metal film(such as a tungsten film, nitride tungsten, a tungsten alloy) is formedon a substrate, and then, a silicon oxide film is formed by a sputteringmethod. A tungsten oxide film in an amorphous state is formed in thevicinity of a boundary at this stage. And after a base film is formed onthe silicon oxide film, various kinds of circuits, elements, and wiringsare formed. When various kinds of circuits, elements, wirings areformed, a film including hydrogen (an amorphous silicon film, a siliconnitride film, a DLC film or the like) is formed, and separation canoccur within the layer or at the interface of a crystallized tungstenoxide film in a later separation step by performing a process having aheat treatment of 400° C. or more. When a TFT is formed, an active layermay be formed by using an amorphous silicon film including hydrogen.

In addition, in the case of a wiring or the like, after a siliconnitride film including hydrogen is formed to cover a wiring, separationcan occur by performing a heat treatment of 400° C. or more.Alternatively, after an amorphous silicon film including hydrogen isformed to cover a wiring and a heat treatment of 400° C. or more isperformed therein, the silicon film may be etched and removed.

Note that, in the above separation methods, a substrate is not requiredto be light-transmitting, and there is no particular limitations on thesubstrate as long as the substrate can withstand a heat treatment of400° C. or more.

A structure of the present invention to realize the above describedstructures is a method of manufacturing a semiconductor device, having afirst step of forming a layer to be separated including an inductor, acapacitor, a resistor element, a SAW element, or a TFT over a firstsubstrate; a second step of applying an organic resin film that issoluble in a solvent, over the layer to be separated; a third step ofattaching a second substrate to the organic resin film by a firsttwo-sided tape and sandwiching the layer to be separated and the organicresin film with the first substrate and the second substrate; a fourthstep of separating the first substrate from the layer to be separated bya physical means; a fifth step of attaching a third substrate to thelayer to be separated by an adhesive agent and sandwiching the layer tobe separated with the second substrate and the third substrate; a sixthstep of separating the layer to be separated and the first two-sidedtape from the second substrate; a seventh step of separating the layerto be separated from the first two-sided tape; an eighth step ofremoving the organic resin film by the solvent; and a tenth step ofconnecting an electrode provided in the third substrate and an electrodeprovided in the layer to be separated.

In the above described structure, one feature is that a method ofconnecting the electrode provided in the third substrate and theelectrode provided in the layer to be separated is a soldering method, amethod by an adhesive agent containing electrical conductive particles,a thermocompression method, a wire bonding method, or a flip chipmethod.

Another structure of the present invention regarding the method ofmanufacturing is a method of manufacturing a semiconductor device,having a first step of forming a layer to be separated including anembedded wiring over a first substrate; a second step of forming aninductor, a capacitor, a resistor element, a SAW element, or a TFT andan extraction electrode connected to the elements over a secondsubstrate; a third step of attaching the second substrate to the layerto be separated by an adhesive agent and sandwiching the layer to beseparated with the first substrate and the second substrate; and afourth step of separating the first substrate from the layer to beseparated by a physical means.

In the above described structure, the embedded wiring is formed by afirst step of forming an etching stopper layer having an electricconductivity on an insulating surface; a second step of forming a firstinsulating film covering the etching stopper; a third of etching thefirst insulating film and forming an opening that reaches the etchingstopper; a fourth step of forming a seed, performing plating and formingan embedded wiring covering the opening; and a fifth step of performinga planarizing process.

It should be noted that a heat treatment of 400° C. or more may beperformed after a planarizing process so that the layer to be separatedcan be easily separated, although separation does not occur even whenthe planarizing process (such as CMP) is performed in the step offorming the embedded wiring.

In the above described structure, one feature is that the embeddedwiring is copper, silver, gold or an alloy of them.

According to the present invention, various functions can be given to amobile terminal. For example, a layer to be separated including a CPUcircuit and a circuit having a GPS function is formed on a substrateaccording to the present invention, the layer to be separated isseparated from the substrate, and can be transferred to and mounted on acircuit board. Alternatively, a layer to be separated including acircuit having a GPS function is formed on a substrate, the layer to beseparated can be separated from the substrate, transferred to asubstrate provided with a CPU circuit, and laminated for integration.Note that GPS (Global Positioning System) is a system for receiving asignal transmitted from a satellite for GPS, obtaining the timedifference, and positioning based on it.

In addition, the present invention can be applied to a multilayerlamination component used for a high frequency circuit, for example, acoupler, a mixer, a distributor, a VCO (a voltage controlledoscillator), a chip antenna and the like.

Effect of the Invention

According to the present invention, further weight saving, thinning,lower cost, mounting area reduction can be realized, and various complexcircuits can be integrated.

INDUSTRIAL APPLICABILITY

According to the present invention, a part or all parts of an electronicdevice can be manufactured by an assembly to which a plastic sheetprovided with various functional circuits or elements is connected, andfurther lightweight of an information terminal device is realized

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A-1E are views showing Embodiment Mode 9.

FIGS. 2A-2D are views showing Embodiment Mode 1.

FIGS. 3A-3E are views showing Embodiment Mode 2.

FIGS. 4A-4D are views showing Embodiment Mode 3.

FIGS. 5A-5F are views showing Embodiment Mode 4.

FIGS. 6A-6F are views showing Embodiment Mode 5.

FIGS. 7A-7F are views showing Embodiment Mode 6.

FIGS. 8A-8E are views showing Embodiment Mode 7.

FIGS. 9A-9B are view showing Embodiment Mode 8.

FIGS. 10A-10B are views showing Embodiment 1.

FIGS. 11A-11B are views showing a cross section TEM picture beforeseparation. (Embodiment Mode 2)

FIGS. 12A-12B are views showing a cross section TEM picture afterseparation. (Embodiment Mode 2)

FIGS. 13A-13D are views showing Embodiment 2.

DETAILED DESCRIPTION OF THE INVENTION

Embodiment Modes of the present invention are described hereinafter.

Embodiment Mode 1

An example is shown here, in which a laminated capacitor or a laminatedinductor is formed without using a semiconductor substrate, transferredto and mounted on a circuit board (printed board).

First, a heat-resisting glass substrate (e.g. a quartz substrate) or aceramics substrate is prepared.

An example which a laminated capacitor is formed on a substrate (a firstsubstrate 300) is described with reference to FIGS. 2 (A) to 2 (C). Aceramic substrate is employed in this embodiment since baking at a hightemperature is performed. A metal film 301 a, here, a tungsten film(from 10 nm to 200 nm in the film thickness, preferably, from 50 nm to75 nm) is formed by a sputtering method on this ceramic substrate, andfurther, an oxide film 302, here a silicon oxide film (from 150 nm to200 nm in the film thickness) is laminated without being exposed to theair. The film thickness of the oxide film 302 is preferably equal to ormore than twice the film thickness of the metal film. Note that inlaminating, a metal oxide film (a tungsten oxide film) in an amorphousstate is formed with about from 2 nm to 5 nm in thickness between themetal film 301 a and the silicon oxide film 302. In separating it in alater step, separation occurs within the tungsten oxide film, at aninterface between the tungsten oxide film and the silicon oxide film, orat an interface between the tungsten oxide film and the tungsten film.

The deposited tungsten film, oxide tungsten film, and silicon oxide filmon an edge face of the substrate are preferably removed selectively byO₂ ashing, since they are formed on the edge face of the substrate by asputtering method.

Then, a silicon oxynitride film (100 nm in film thickness) (not shown inthe figure) to be a base insulating film is formed by a PCVD method, andfurther a silicon nitride film including hydrogen (100 nm in filmthickness) is laminated as a hydrogen containing film 303 without beingexposed to the air.

Then, a paste for an internal electrode layer and a paste for adielectric layer are laminated by a sheet method or a printing method,and then baked. Here is shown an example in which a paste for aninternal electrode layer and a paste for a dielectric layer are printedand laminated by using a printing method, and cut into a predeterminedshape, and then, separated from the substrate to form a green chip.

Ceramic of an alumina system having a favorable high frequency property,ceramic of a BaTiO₃ system in paste form, or the like is used for amaterial of a dielectric layer 305. Copper, silver, nickel, tin, zinc,Pd, aluminum or the like is used for a material of an internal electrode304, and is laminated so that each edge face thereof is alternatelyexposed in facing two surfaces of a capacitor chip body. (FIG. 2 (A))Note that the bake temperature is from 850° C. to 1400° C. Further, ametal oxide film 301 b having a crystal structure is obtained in baking.

Then, it is bonded to a circuit board or a film 308 by an adhesive agent306. Note that a terminal 307 or a wiring (not shown in the figure) isformed in the circuit board or the film, and various circuits or chipscan be mounted thereon.

Then, the first substrate 300 is separated. Separation occurs within thetungsten oxide film, at an interface between the tungsten oxide film andthe silicon oxide film, or at an interface between the tungsten oxidefilm and the tungsten film (FIG. 2 (B)).

Then, after the tungsten oxide left on the surface is removed, anexternal electrode 309 is formed. The external electrode 309 is formedby burning of a conductive paste and plating. Note that the tungstenoxide left on the surface is not needed to be removed, and there are noparticular limitations on it. A capacitor circuit is configured byforming a paste for the external electrode on the facing two surfaces ofthe capacitor chip body. (FIG. 2 (C)) A terminal is connected at thesame time as forming the external electrode 309 here, but after theexternal electrode 309 is formed, a connection with the terminal may beperformed with an electrode or a solder for connecting.

Note that a capacitor is an element that has a great demand forso-called decoupling use, which is used between a power supply line anda ground for a stabilization of a power supply or an EMC measure in eachcircuit block.

In addition, an inductor can be also formed similarly.

According to the method for forming a capacitor, a tungsten film and asilicon oxide film are laminated by a sputtering method on a ceramicsubstrate, and a tungsten oxide film is formed in forming the siliconoxide film. A silicon oxynitride film (100 mm in film thickness) (notshown in the figure) to be a base insulating film is formed by a PCVDmethod, and further a silicon nitride film including hydrogen (100 nm infilm thickness) is laminated as a hydrogen containing film without beingexposed to the air.

Then, a paste for an internal electrode layer and a paste for a magneticmaterial layer are laminated by a sheet method or a printing method, andthen baked.

A substance that Ni—Cu—Zn system ferrite, Mn—Mg—Zn system ferrite arekneaded into paste form by a binder such as a methyl cellulose orbutyral resin is used for a material of a magnetic material layer 315.Copper, silver, nickel, tin, zinc, Pd, aluminum or the like is used fora material of an internal electrode 314 a and laminated in a coiledshape. Note that it is laminated so that an extraction electrode portion314 b of the internal electrode in a coiled shape is exposed in an edgeface.

Then, it is bonded to a circuit board or a film by an adhesive agent.

Then the first substrate is separated. Separation occurs within thetungsten oxide film, at an interface between the tungsten oxide film andthe silicon oxide film, or at an interface between the tungsten oxidefilm and the tungsten film.

Then, after removing the tungsten oxide left on the surface, a terminalelectrode 319 is formed. The terminal electrode 319 is formed by burningof a conductive paste and plating. An inductor circuit is configured byforming a paste for the terminal electrode on facing two surfaces of aninductor chip body (FIG. 2 (D)).

In addition, an LC filter can be formed by laminating the capacitor andthe inductor integrally. A complex lamination body can be formed bylaminating for forming an inductor portion after laminating for forminga capacitor portion, according to the above method for manufacturing.

According to the present invention, an LPF (Low Pass Filter) that isrepresentative as an LC filter can be formed. An LPF is a high frequencycircuit included in a module such as a cellular phone and is employedfor a use of removing harmonic components of a power amplifier, anantenna switch or a VCO. An LPF comprises two Ls (inductors), and fiveCs (capacitors). A suitable zero point is provided in an attenuationband of two LC parallel resonant circuits, and second harmonic, thirdharmonic of passage frequency are removed with a good balance, and aninsertion loss of the passband as LPF is optimized to be minimized bysetting impedance to 50Ω by a Cs (capacitors) disposed in input andoutput.

In addition to an LPF, various kinds of an LC filter, for example, aBPF, a diplexer, a coupler (a directional coupler), a balun and thelike, can be manufactured by combining a capacitor or an inductor.

Embodiment Mode 2

An example in which a capacitor element and a TFT are formed,transferred to and mounted on a circuit board (printed board) is shownhere.

Note that the same reference numerals are used for the same portions,since up to a halfway step is performed similarly to Embodiment Mode 1.

A tungsten film 301 a and a silicon oxide film 302 are laminated by asputtering method over a first substrate 300, and a tungsten oxide filmin an amorphous state is formed in forming the silicon oxide film. Asilicon oxynitride film (100 nm in film thickness) (not shown in thefigure) to be a base insulating film is formed by a PCVD method, andfurther an amorphous silicon film including hydrogen (55 nm in filmthickness) is laminated as a hydrogen containing film without beingexposed to the air. Herein, a quartz substrate is used as the firstsubstrate 300.

A hydrogen concentration of the amorphous silicon film includinghydrogen was measured through FT-IR. As a result, Si—H was 1.06×10²²(atoms/cm³), Si—H₂ was 8.34×10¹⁹ (atoms/cm³), and the calculatedhydrogen concentration in the composition ratio was 21.5%. Further, thehydrogen concentration was similarly calculated under the changed filmdeposition conditions of a PCVD method, as a result of which theobtained hydrogen concentrations in the composition ratio were 16.4%,17.1%, and 19.0%.

Thereafter, the amorphous silicon film is crystallized by using a knowntechnique (such as a solid-phase growth method, a laser crystallizationmethod, a crystallization method using catalyst metal) to form anelement using a TFT having a polysilicon film as an active layer.Herein, a polysilicon film is obtained by a crystallization method usinga catalyst metal. A nickel acetate salt solution containing nickel of 10ppm by weight is applied by a spinner. Note that nickel elements may beapplied on the entire surface by sputtering instead of applying. Then, aheat treatment is carried out for crystallization to form asemiconductor film having a crystal structure (here, a polysiliconlayer). Herein, a silicon film having a crystal structure is obtained bya heat treatment for crystallization (at 550° C. for 4 hours) after theheat treatment (at 550° C. for one hour).

The amorphous silicon film contains hydrogen. In the case of forming apolysilicon film by heating, a heat treatment of at least 410° C. isperformed thereby diffusing hydrogen as well as forming the polysiliconfilm. An amorphous metal oxide film is crystallized by a heat treatmentof at least 400° C. As a result, a metal oxide film 301 b having acrystal structure can be obtained. FIG. 11 shows a cross-sectional TEMpicture. Accordingly, the metal oxide film having a crystal structure isformed and hydrogen is diffused by performing a heat treatment of atleast 410° C. After the heat-treatment of at least 410° C. is finished,the separation in the tungsten oxide film, or at an interface betweenthe tungsten oxide film and the silicon oxide film, or an interfacebetween the tungsten oxide film and the tungsten film can be achievedwith relatively little force (for example, human hands, wind pressure ofa gas blown from a nozzle, ultrasonic waves, or the like). Note that,when a heat treatment is performed at a temperature enough to obtain ametal oxide film having a crystal structure, the thickness of the metaloxide film is thinned slightly.

Various elements typified by a TFT (a thin film diode, a silicon-basedpin-junction photoelectric transducer, a silicon resistor element, or asensor element (typically, a pressure-sensitive fingerprints sensorusing polysilicon)) can be also formed by using the obtained polysiliconfilm.

Next, after the oxide film on the surface of the silicon film having acrystal structure is removed by dilute hydrofluoric acid or the like,irradiation of laser light (XeCl: wavelength of 308 nm) for raising adegree of crystallization and repairing defects left in crystal grainsis performed in the atmosphere or in an oxygen atmosphere. Excimer laserlight with a wavelength of 400 nm or less, or second harmonic wave orthird harmonic wave of a YAG laser is used for the laser light. Here,pulsed laser light with a repetition frequency of approximately 10 to1000 Hz is used, the laser light is condensed to 100 to 500 mJ/cm² by anoptical system, and irradiation is performed with an overlap ratio of 90to 95%, thereby the silicon film surface may be scanned. Here, theirradiation of the laser light is performed in the atmosphere with arepetition frequency of 30 Hz and energy density of 470 mJ/cm². Notethat an oxide film is formed on the surface by the laser lightirradiation since the irradiation is conducted in the atmosphere or inan oxygen atmosphere. Though an example of using the pulsed laser isshown here, a continuous wave laser may also be used. Whencrystallization of an amorphous semiconductor film is conducted, it ispreferable that the second harmonic through the fourth harmonic of basicwaves is applied by using a solid state laser which is capable ofcontinuously oscillating in order to obtain a crystal in a large grainsize. Typically, it is preferable that the second harmonic (532 nm) orthe third harmonic (355 nm) of an Nd: YVO₄ laser (basic wave of 1064 nm)is applied. In the case of using a continuous wave laser, laser lightemitted from the continuous wave type YVO₄ laser with 10 W output isconverted into harmonics by using non-linear optical elements. Also, amethod of emitting harmonics by applying YVO₄ crystal and the non-linearoptical elements into a resonator can be cited. Then, preferably, thelaser light is formed so as to have a rectangular shape or an ellipticalshape on an irradiated face by an optical system, thereby irradiating anobject to be treated. At this time, the energy density of approximately0.01 to 100 MW/cm² (preferably 0.1 to 10 MW/cm²) is required. Thesemiconductor film may be moved at approximately 10 to 2000 cm/s raterelatively corresponding to the laser light so as to be irradiated.

Then, a barrier layer made of an oxide film having a thickness of 1 to 5nm in total is formed by treating the surface with ozone water for 120seconds, in addition to the oxide film formed by this laser lightirradiation. The barrier layer is formed in order to remove nickel thatis added for crystallization from the film. Though the barrier layer isformed by using ozone water here, a barrier layer may be formed bydepositing an oxide film of about 1 to 10 nm thick by a method ofoxidizing a surface of a semiconductor film having a crystal structureby ultraviolet irradiation in an oxygen atmosphere, a method ofoxidizing a surface of a semiconductor film having a crystal structureby an oxygen plasma treatment, a plasma CVD method, a sputtering method,a vapor deposition or the like. Further, before forming the barrierlayer, the oxide film formed by laser light irradiation may be removed.

On the barrier layer, an amorphous silicon film containing an argonelement is formed to be 10 nm to 400 nm thick, herein, 100 nm thick bysputtering to serve as a gettering site. Here, the amorphous siliconfilm containing an argon element is formed under an atmospherecontaining argon with using a silicon target. When a plasma CVD methodis used for forming the amorphous silicon film containing an argonelement, the deposition condition is as follows: a flow ratio ofmonosilane to argon (SiH₄: Ar) is set to be 1:99; a deposition pressureis set to be 6.665 Pa (0.05 Torr); an RF power density is set to be0.087 W/cm²; a deposition temperature is set to be 350° C.

Thereafter, a furnace heated at 650° C. is used for a heat treatment forthree minutes for gettering to reduce the nickel concentration in thesemiconductor film having a crystal structure. A lamp annealingapparatus may be used instead of the furnace.

Subsequently, the amorphous silicon film containing the argon element,which is a gettering site, is selectively removed with the barrier layeras an etching stopper, and then, the barrier layer is selectivelyremoved by dilute hydrofluoric acid. Note that there is a tendency thatnickel is likely to move to a region with a high oxygen concentration ingettering, and thus, it is desirable that the barrier layer made of theoxide film is removed after gettering.

Note that, in the case where crystallization using a catalytic elementis not performed, the above described steps such as the formation of abarrier layer, the formation of a gettering site, a heat treatment forgettering, the removal of a gettering site, and the removal of a barrierlayer are not necessary.

Then, after a thin oxide film is formed with ozone water on the surfaceof the obtained silicon film having a crystal structure (also referredto as polysilicon film), a mask made of resist is formed, and an etchingtreatment is conducted to obtain a desired shape, thereby forming theisland-like semiconductor layers separated from one another. After theformation of the semiconductor layers, the mask made of resist isremoved.

Next, the oxide film is removed with an etchant containing hydrofluoricacid, and at the same time, the surface of the silicon film is washed.Thereafter, an insulating film containing silicon as its main component,which serves as a gate insulating film, is formed. In this embodiment, asilicon oxynitride film (composition ratio: Si=32%, O=59%, N=7%, H=2%)is formed to have a thickness of 115 nm by a plasma CVD method.

Thereafter, a gate electrode is formed over a gate insulating film, andformation of a source region or a drain region by doping to an activelayer, formation of an interlayer insulating film (an inorganicinsulating film), formation of a source electrode or a drain electrode,an activation treatment, a hydrogenation treatment etc. are performedappropriately, thereby forming a top gate TFT 403 which has apolysilicon film as an active layer. When phosphorus imparting n-type isadded as an impurity element to be doped, an n-channel TFT can beformed. When boron imparting p-type is added, a p-channel TFT can beformed. A CMOS circuit can be manufactured by combining these TFTs.

Note that the example of a top gate type is shown as a structure of aTFT here, but the structure of a TFT may be a bottom gate type or asequence staggered type, for example, specifically without beinglimited.

Then, an interlayer insulating film covering the TFT is formed, and acapacitor 404 comprising a lower electrode 404 a, a high dielectric thinfilm 404 b and an upper electrode 404 c is formed over the interlayerinsulating film. For the high dielectric thin film (dielectric thin filmhaving a high dielectric constant) 404 b, BST (BaSrTiO₃), STO (SrTiO₃)or PZT (PbZrTiO₃) may be employed. A heat treatment of 600 to 700° C. isperformed to obtain these high dielectric thin films. Note that a metalmaterial which is stable to a material of the high dielectric thin filmis used for the lower electrode 404 a or the upper electrode 404 c.

Then, an interlayer insulating film covering the capacitor is formed,and a contact hole is formed in the interlayer insulating film to forman extraction electrode. An extraction electrode connected to a TFT, anextraction electrode connected with the lower electrode of thecapacitor, an extraction electrode connected with the upper electrodethereof, and the like are each formed herein (FIG. 3 (A)).

Next, an adhesive agent that is soluble in water or alcohol is appliedover the whole surface and baked. The composition of the adhesive agentmay be any composition, for example, epoxy series, acrylate series,silicone series, and the like. Here, a resin layer (a thickness of 30μm) formed of water-soluble resin (TOAGOSEI Co., Ltd.: VL-WSHL10) 410 isspin-coated, and exposed to light for two minutes to be temporarilycured, then, exposed its back to UV rays for 2.5 minutes, and then,exposed its surface for 10 minutes, namely, it is fully cured by thelight-exposure of 12.5 minutes in total. The water-soluble resin filmserves as a planarizing film. Thus, when the substrate is bonded later,it is possible that a surface of the planarizing film and the substrateface are almost parallel to each other. When this water soluble resinfilm is not used, there is a danger that the unevenness by an electrodeor a TFT is generated in pressure-bonding.

Then, a second substrate 412 is bonded to the resin layer 410 by usingan adhesive layer (two-sided tape) 411 (FIG. 3(B)). Note that anadhesive agent that can be separated by ultraviolet irradiation may beused instead of the two-sided tape.

The first substrate 300 provided with the metal film 301 a is separatedby a physical means. The first substrate 300 can be separated withrelatively little force (for example, human hands, wind pressure of agas blown from a nozzle, ultrasonic waves, or the like). Thus, a layerto be separated formed on the silicon oxide layer 302 can be separatedfrom the first electrode 300. FIG. 3(C) shows a state after theseparation. Note that FIG. 12 shows a cross-sectional TEM picture of thefirst substrate after the separation. The TEM pictures in FIG. 12 andFIG. 11 show different parts and they do not correspond to each other.As shown in FIG. 12, the oxide tungsten film is partly thin and partlynonexistent. The tungsten oxide film partly remains in the separatedlayer; however, it is transparent, and thus the tungsten oxide film maynot removed or removed.

Then, it is bonded to a circuit board or a film 413 by an adhesive agent414 (FIG. 3 (D)). A terminal 415 or a wiring (not shown in the figure)is formed in the circuit board or the film, and various circuits orchips can be mounted thereon.

Then, the second substrate 412 is separated from the two sided tape 411,and the two-sided tape is peeled. And the resin layer 410 made of watersoluble resin is dissolved in water and removed.

Then, a bonding wire 416 for connecting an extraction electrode and theterminal 415 is formed. Alternatively, the extraction electrode and theterminal 415 may be connected by soldering or a conductive adhesiveagent.

By the present invention, a layer to be separated including a capacitorelement and a TFT can be mounted on a circuit board. A nonvolatile RAMor a high integration DRAM can be manufactured without using asemiconductor substrate by applying the present invention.

In addition, an operational amplifier (op-amp) in which an n-channel TFTor a p-channel TFT is appropriately combined, can be manufactured.

Further, this embodiment mode can be combined with Embodiment Mode 1,and the inductor shown in Embodiment Mode 1 can be laminated, forexample, and thus various high frequency circuits can be realized.

Embodiment Mode 3

An example of a mounting method that is different from that shown inEmbodiment Mode 2 is shown in FIG. 4 herein.

Here, a CMOS circuit in which a p-channel TFT 303 a and an n-channel TFT303 b are complementarily combined is formed.

First, the p-channel TFT 303 a and the n-channel TFT 303 b are formed ona first substrate according to Embodiment Mode 2 (FIG. 4 (A)). Since itis possible that the process temperature in forming a CMOS circuit iscontrolled to be equal to or less than 600° C., a glass substrate can beused in this embodiment mode for the first substrate 300.

When a state of FIG. 4 (A) is obtained, a circuit board 510 providedwith a terminal 509 is bonded to the first substrate 300 by an adhesiveagent 508 b containing electrical conductive particles 508 a (FIG.4(B)). The terminal 509 and an extraction electrode connected to a TFTare electrically connected via the electrical conductive particles bybonding them.

Then, the first substrate 300 is separated. Separation occurs within thetungsten oxide film, at an interface between the tungsten oxide film andthe silicon oxide film, or at an interface between the tungsten oxidefilm and the tungsten film (FIG. 4 (C)).

Then, after removing the tungsten oxide left on the surface, a heat sink512 is bonded by an adhesive agent 511 (FIG. 4 (D)). Specifically, whena highly integrated circuit such as a CPU circuit is formed by using aCMOS circuit, since heat easily generates, it is useful to bond the heatsink for radiating heat of an element. Note that the heat sink is notnecessarily provided in the case of an integrated circuit to which heatgeneration does not matter.

In addition, this embodiment mode can be freely combined with EmbodimentMode 1 or Embodiment Mode 2, and various complex integrated circuits canbe realized without using a semiconductor substrate.

Embodiment Mode 4

Herein, an example in which a surface acoustic wave (SAW) element isformed, transferred to and mounted on a circuit board (printed board)without using a semiconductor substrate, is shown in FIG. 5. The SAWelement has a structure in which a surface wave propagation film and apiezoelectric film are laminated, and a surface wave is excited to thesurface wave propagation film by applying an electric field to thepiezoelectric film by a comb type electrode, and oscillating.

Note that the same reference numerals are used for the same elements,since up to a halfway step is performed similarly to Embodiment Mode 1.

A tungsten film 301 a, a silicon oxide film 302 are laminated by asputtering method over a first substrate 300, and in the case of formingthe silicon oxide film, a tungsten oxide film in an amorphous state isformed. A silicon oxynitride film (100 nm in film thickness) (not shownin the figure) to be a base insulating film is formed by a PCVD method,and further a surface wave propagation film 603 is laminated withoutbeing exposed to the air. Note that herein a quartz substrate is used asthe first substrate 300 and a DLC film containing hydrogen (10 to 50 μmin film thickness) is used as the surface wave propagation film 603. Afilm formation method of the DLC film is not limited particularly, andmay be a CVD method, a microwave CVD method, a PVD method, a sputteringmethod, an ion plating method or the like.

Then, a comb type electrode 602 is formed. The comb type electrode 602is not limited specifically, as far as it is a conductive material. Inaddition, the thickness of the comb type electrode 602 is preferablyaround 10 to 500 nm. In addition, a plane shape of the comb typeelectrode 602 may be a single electrode shown in FIG. 5 (F), or may be adouble electrode. In addition, the example in which the comb typeelectrode 602 is formed on the surface wave propagation film 603 isshown here, but a depression may be formed in the surface wavepropagation film 603 to bury it.

Then, a piezoelectric material film 604 is formed (FIG. 5(A)). ZnO, AlN,a quartz crystal, LiNbO₃, LiTaO₃ or the like may be employed for thepiezoelectric material film 604. The thickness of this piezoelectricmaterial film 604 can be selected appropriately depending on the type ofmaterial or intended characteristics (such as center frequency,fractional band width, temperature characteristic) of a surface acousticwave element. A film formation method of the piezoelectric material film604 may be a CVD method, a microwave CVD method, a PVD method, asputtering method, an ion plating method or the like, without beinglimited specifically.

Then, an adhesive agent that is soluble in water or alcohols is appliedto the entire surface and baked. For example, an epoxy system, anacrylate system, a silicone system and the like may be used for acomposition of this adhesive agent. Herein, a resin layer 610 (filmthickness of 30 μm) made of water soluble resin (VL-WSHL10 made byTOAGOSEI CO. LTD) is applied by spin-coating and cured. This watersoluble resin film functions as a planarizing film. Thus, when thesubstrate is bonded later, it is possible that a surface of theplanarizing film and the substrate face are almost parallel to eachother. When this water soluble resin film is not used, there is a dangerthat the unevenness by an electrode of a TFT is generated inpressure-bonding.

Then, a second substrate 612 is bonded to the resin layer 610 by usingan adhesive layer (a two-sided tape) 611 (FIG. 5(B)). Note that anadhesive agent that can be peeled off by ultraviolet irradiation, forexample, may be used instead of the two-sided tape.

Then, the first substrate 300 for which the metal film 301 a is providedis separated by a physical means. Note that it can be separated withrelatively little force (for example, human hands, wind pressure of agas blown from a nozzle, ultrasonic waves, or the like) by heating at400° C. or more in a treatment during or after forming a DLC film. Thus,a layer to be separated formed over the silicon oxide layer 302 can beseparated from the first substrate 300. FIG. 5(C) shows a state afterthe separation. The tungsten oxide film which has been partially left onthe layer to be separated may be removed or not, since it istransparent.

Then, a circuit board or a film 614 is bonded by an adhesive agent 613(FIG. 5(D)). A terminal or a wiring (not shown in the figure) is formedon the circuit board or the film so that various circuits or chips canbe mounted thereon.

According to this embodiment mode, a SAW element which employs a plasticfilm as a support medium can be manufactured, and when it is bonded to aplastic film having a wiring, their coefficients of thermal expansioncan be adjusted to each other and thus, a warp of the whole device canbe prevented.

The second substrate 612 is separated from the two-sided tape 611, thentwo-sided tape is peeled. The resin layer 610 made of the water solubleresin is dissolved and removed by using water (FIG. 5(E)). FIG. 5(F)shows a top view.

According to the present invention, a layer to be separated including asurface acoustic wave element (a SAW element) can be mounted on acircuit board. This surface acoustic wave element can be applied to afilter, a delay line, an oscillator, a resonator, a convolver and acorrelator and the like, and typically, is interposed between stages oftransmitting and receiving and can constitute a BPF (bandpass filter)removing an unnecessary frequency component, in a high frequency circuitof a cellular phone. Further, a SAW element can manufacture a duplexerfor combining a BPF having a transmitting frequency in a passband and aBPF having a receiving frequency in a passband and sharing an antennaterminal.

In the surface acoustic wave element, an electrode for a short-circuitmay be formed if necessary. The electrode for a short-circuit is anelectrode having a function to change SAW characteristics of the elementby making the electric field equipotential. Further, in the surfaceacoustic wave element, a protective film may be formed if necessary.

This embodiment mode can be freely combined with Embodiment Modes 1 to3.

Embodiment Mode 5

An example of forming a semiconductor resistor element, transferring itto a circuit board (printed board), and mounting it thereon withoutusing a semiconductor substrate, is described herein.

Note that the same reference numerals are used for the same elements,since up to a halfway step is performed similarly to Embodiment Mode 1.

A tungsten film 301 a, a silicon oxide film 302 are laminated by asputtering method over a first substrate 300, and in the case of formingthe silicon oxide film, a tungsten oxide film in an amorphous state isformed. A silicon oxynitride film (100 nm in film thickness) (not shownin the figure) to be a base insulating film is formed by a PCVD method,and further an amorphous silicon film including hydrogen (50 to 100 nmin film thickness) is laminated as a semiconductor film 702 withoutbeing exposed to the air. Herein, a quartz substrate is used as thefirst substrate 300.

Then, a heat treatment of 400° C. or more is performed to crystallize ametal oxide film in an amorphous state and obtain a metal oxide film 301b having a crystal structure. Alternatively, a polysilicon film may beformed by heating at 600° C. or more. Then, an n-type impurity element(such as phosphorus) or a p-type impurity element (such as boron) isdoped into the semiconductor film 702 to obtain a desired resistancevalue.

Then, after the semiconductor film is made to have a desired shape, awiring, an interlayer insulating film and an extraction electrode areformed (FIG. 6(A)). FIG. 6(E) shows a top view and FIG. 6(F) shows anequivalent circuit diagram. Note that resistance value of asemiconductor resistor element is determined by width W, length L, andsheeting resistance value of a semiconductor portion that is to be aresistor.

When the state of FIG. 6 (A) is obtained, a circuit board 710 providedwith terminals 709 a and 709 b is bonded to the first substrate 300 byan adhesive agent 708 b including electrical conductive particles 708 a(FIG. 6 (B)). The terminals 709 a and 709 b are electrically connectedto an extraction electrode connected to the semiconductor film 702 viathe electrical conductive particles by bonding them.

Then, the first substrate 300 is separated. Separation occurs within thetungsten oxide film, at an interface between the tungsten oxide film andthe silicon oxide film, or at an interface between the tungsten oxidefilm and the tungsten film (FIG. 6 (C)).

Then, after removing the tungsten oxide left on the surface, a heat sink712 is bonded by an adhesive agent 711. Specifically, resistance of thesemiconductor resistor element is determined by generating heat, thus itis useful to bond the heat sink for radiating heat of an element.

In addition, a thin film resistor element can be formed by using amaterial such as TaN_(x) or NiCr, as well as the above semiconductorresistor element.

This embodiment mode can be freely combined with Embodiment Modes 1 to4. For example, when it is combined with Embodiment Mode 2, a capacitorhaving a large capacity, a TFT and a semiconductor resistor element canbe manufactured simultaneously.

Embodiment Mode 6

Herein, an example in which a spiral inductor is formed, transferred toa circuit board (printed board) and mounted thereon is shown in FIG. 7.The spiral inductor is an inductor that is wound in spiral like with atransmission line of high impedance, imaging a winding electric coil.

Note that the same reference numerals are used for the same elements,since up to a halfway step is performed similarly to Embodiment Mode 1.

A tungsten film 301 a, a silicon oxide film 302 are laminated by asputtering method over a first substrate 300, in the case of forming thesilicon oxide film, a tungsten oxide film in an amorphous state isformed. A silicon oxynitride film (100 nm in film thickness) (not shownin the figure) to be a base insulating film is laminated by a PCVDmethod.

Then, a transmission line 801 is formed. The transmission line 801 isnot limited specifically, as far as it is a conductive material. Herein,the transmission line is wound up in spiral like about three times atregular intervals.

Subsequently, an interlayer insulating film, a hydrogen containing film803 and an extraction electrode 802 are formed (FIG. 7(A)). Note thatFIG. 7 (F) shows a top view. A silicon nitride film containing hydrogenis used for the hydrogen containing film 803.

Then, an adhesive agent that is soluble in water or alcohols is appliedto the entire surface and baked. For example, an epoxy system, anacrylate system, a silicone system or the like may be used for acomposition of this adhesive agent. Herein, a resin layer 810 (filmthickness of 30 μm) made of water soluble resin (VL-WSHL10 made byTOAGOSEI CO., LTD) is applied by spin-coating and cured. This watersoluble resin film functions as a planarizing film. Thus, when thesubstrate is bonded later, it is possible that a surface of theplanarizing film and the substrate face are almost parallel to eachother. When this water soluble resin film is not used, there is a dangerthat the unevenness by an electrode or a TFT is generated inpressure-bonding.

Then, a second substrate 812 is bonded to the resin layer 810 by usingan adhesive layer (a two-sided tape) 811 (FIG. 7(B)). Note that anadhesive agent that can be peeled off by ultraviolet irradiation, forexample, may be used instead of the two-sided tape.

Then, the first substrate 300 for which the metal film 301 a is providedis separated by a physical means. Note that it can be separated withrelatively little force (for example, human hands, wind pressure of agas blown from a nozzle, ultrasonic waves, or the like) by heating at400° C. or more in a treatment during or after forming the hydrogencontaining film 803. Thus, a layer to be separated formed over thesilicon oxide layer 302 can be separated from the first substrate 300.FIG. 7(C) shows a state after the separation. The tungsten oxide filmwhich has been partially left on the layer to be separated may beremoved or not, since it is transparent.

Then, a circuit board or a film 814 is bonded by an adhesive agent 813(FIG. 7(D)). A terminal or a wiring (not shown in the figure) is formedon the circuit board or the film so that various circuits or chips canbe mounted thereon.

Then, the second substrate 812 is separated from the two sided tape 811,and the two sided tape is peeled. And the resin layer 810 made of watersoluble resin is dissolved by using water and removed (FIG. 7(E)).Through the above described steps, the spiral inductor can be mounted onthe circuit board or the film 814.

According to this embodiment mode, a spiral inductor which employs aplastic film as a support medium can be manufactured, and when it can bebonded to a plastic film having a wiring, their coefficients of thermalexpansion can be adjusted to each other, and thus a warp of the wholedevice can be prevented.

Further, plural spiral inductors may be combined.

This embodiment mode can be freely combined with Embodiment Modes 1 to5.

Embodiment Mode 7

In FIG. 8, an example in which an embedded wiring is formed, transferredonto and mounted on the circuit board (printed board) obtained inEmbodiment Mode 2, is shown herein. An insulating layer is formed, anembedded wiring (Cu, Au, Ag, Ni, chrome, palladium, rhodium, tin, leador an alloy thereof or the like) is formed in the insulating layer.After a surface of the insulating layer is flattened, a metal protectivefilm (such as Ti, TiN, Ta, TaN) is formed in an exposed portion.

Initially, a metal film 901 a, herein a tungsten film (film thickness of10 nm to 200 nm, preferably, 50 nm to 75 nm) is formed by a sputteringmethod on a substrate 900 having an insulating surface, and further anoxide film 902, herein a silicon oxide film (film thickness of 150 nm to200 nm) is laminated without being exposed to the air. Note that a metaloxide film (tungsten oxide film) 901 b of about 2 nm to 5 nm thick thatis an amorphous (in an amorphous state) is formed between the metal film901 a and the silicon oxide film 902, in laminating them. A substratewhose surface is flat is preferably used for the substrate 900 having aninsulating surface, since an embedded wiring is formed in a later step.

Then, a silicon oxynitride film (film thickness of 100 nm) (not shown inthe figure) to be a base insulating film is formed by a PCVD method, anamorphous silicon film (film thickness of 50 nm) containing hydrogen islaminated for a hydrogen containing film 903 without being exposed tothe air.

Then, an etching stopper layer 905 a is formed. An element selected fromNi, Ti, W, WSi_(x), Al, Mo, Ta, Cr or Mo, or an alloy material mainlycontaining the element described above, a film mainly containing acompound material or a laminated film thereof may be used for theetching stopper layer 905 a. The etching stopper layer 905 a is also aseed layer (cathode by plating) of an electrolytic plating treatment tobe performed later. Further, a seed layer may be formed over the etchingstopper layer 905 a separately. Then, an insulating film containingmainly silicon covering the etching stopper layer 905 a is formed.

Then, pattering is performed, the insulating film is selectively etchedto form an opening (groove) that reaches the etching stopper layer 905a. Then, after a first barrier layer is formed, an electrolytic platingtreatment is conducted to form a low resistance metal film having anadequate thickness in the opening (groove). The electrolytic platingtreatment is a method by which a metal film is formed in a cathode faceby applying a direct current into a solution including a metal ion to beformed by plating. A material having low electric resistance, e.g.copper, silver, gold, chrome, iron, nickel, platinum or an alloy thereofcan be used as a metal to be plated. The thickness of the metal filmformed by the electrolytic plating method can be determinedappropriately by a practitioner by controlling current density and time.Because the electric resistance of copper is extremely low, an exampleof using copper (Cu) that can be electrolytic-plated as the lowresistance metal film is shown here. Further, the first barrier layer isa prevention layer of diffusion for copper that diffuses quickly in theinsulating film 904 mainly containing a silicon oxide, in other words, abarrier metal. A metal material having the specific resistance value ofabout 300 to 500 μΩcm or less, (WN_(x), TaN_(x), TiSi_(x)N_(y),WSi_(x)N_(y), TaSi_(x)N_(y), etc.) is desirably used for the firstbarrier layer. In addition, since copper has unfavorable adhesivenesswith the insulating film 904 containing mainly a silicon oxide, it iseffective to form the first barrier layer having favorable adhesiveness.

By performing a planarizing process typified by chemical mechanicalpolishing (hereinafter, referred to as a CMP method), copper and thefirst barrier layer are left in only the opening (a groove), and anunnecessary portion is removed to form an embedded type wiring(hereinafter, an embedded wiring) 905 b. Note that the adhesiveness atan interface of the metal oxide film 901 b is favorable, since it isamorphous, even when CMP is performed thereon; therefore separation doesnot occur.

Then, a second barrier layer is formed to enhance oxidation resistanceof the exposed copper (FIG. 8(A)). Further, the second barrier layer isalso effective as a prevention layer of diffusion for copper thatdiffuses quickly in the insulating film 904 mainly containing a siliconoxide. A silicon nitride film or a metal material (TiN, NbN, WN_(x),TaN_(x), TiSi_(x)N_(y), WSi_(x)N_(y), TaSi_(x)N_(y), etc.) is desirablyused for the second barrier layer. In addition, since copper hasunfavorable adhesiveness with the insulating film containing mainlysilicon oxide, it is effective to form the second barrier layer havingfavorable adhesiveness.

Then, a heat treatment is performed so as to easily separate a layer tobe separated from the first substrate in a later separation step (FIG.8(B)). This heat treatment crystallizes the metal oxide film 901 b toform a metal oxide film 901 c having a crystal structure, and diffuseshydrogen included in the hydrogen containing film 903. Note that a heattreatment may be performed at 400° C. for one hour or more in the caseof using a tungsten film as the metal film 901 a.

Moreover, an alloy, e.g., a W—Mo alloy, is used as the metal film 901 a,and the degree of separation can be changed by adjusting the compositionratio. In addition, nitrogen may be injected into the metal oxide filmby an ion implantation method or an ion doping method so as not to beeasily separated, or a treatment for easily separating by injectingoxygen may be performed.

Then, the first substrate 900 for which an embedded wiring 905 b isprovided is bonded to a circuit board 413 for which a capacitor element(capacitor 404) and a TFT 403 obtained in Embodiment Mode 2 are providedby an adhesive layer 414 (FIG. 8(C)). The same reference numerals areused for the same portion as that in Embodiment Mode 2. The electricalconduction of the embedded wiring and an electrode that is connected tothe capacitor 404, and the electrical conduction of the embedded wiringand an electrode connected to the TFT 403 are made by bonding by usingan adhesive agent 906 b including electrical conductive particles 906 a.

In addition, when a high dielectric thin film 404 b is formed, it isdifficult to lower resistance value of a wiring, since a highlyheat-resisting material is used for the wiring because a heat treatmentis conducted at a relatively high temperature. A complex circuitprovided with a low resistance wiring can be provided by bonding theembedded wiring in this embodiment mode as a leading wiring portion.

Then, the first substrate 900 for which the metal film 901 a is providedis separated by a physical means. It can be separated with relativelylittle force (for example, human hands, wind pressure of a gas blownfrom a nozzle, ultrasonic waves, or the like). Thus, a layer to beseparated formed over the silicon oxide layer 902 can be separated fromthe first substrate 900. FIG. 8(D) shows a state after the separation.The tungsten oxide film which has been partially left on the layer to beseparated may be removed or not, since it is transparent.

Then, a bonding wiring 416 to connect an extraction electrode and aterminal 415 is formed, like Embodiment Mode 2. In addition, theextraction electrode and the terminal 415 may be connected by solderingor a conductive adhesive agent.

Through the above described steps, the layer to be separated that isprovided with a low resistance embedded wiring and that includes acapacitor element and a TFT can be mounted on a circuit board to beoverlapped. Further, an embedded wiring pattern is formed, andconnection points to the circuit board can be reduced by overlapping thelayer to be separated to be connected, depending on it. In addition, bybonding the low resistance embedded wiring, a complicated circuit havinga leading wiring can be simplified.

Herein, an example of using an embedded wiring of the present inventionas a leading wiring is shown, but is not limited to this in particular.It is can be used for various wirings such as source wiring, a leadingout wiring, a power supply line and a capacitor wiring to lowerresistance of a wiring.

By using an embedded wiring of the present invention, a spiral inductor,an antenna pattern, a ground pattern and the like can be manufactured.

This embodiment mode can be freely combined with Embodiment Modes 1 to6.

Embodiment Mode 8

Various functional circuits can be formed by using one of the abovedescribed embodiment modes 1 to 7 and mounted on a circuit board 100without using a semiconductor substrate, according to the presentinvention. A ceramic board (such as alumina) and a resin systemsubstrate (such as FR-4) may be employed for the circuit board 100.

Herein, FIG. 9(A) shows a perspective view of a module having a highfrequency circuit (front end portion) and a CPU to be mounted on aninformation terminal such as a cellular phone.

The front end portion is formed by integrating two antenna switches, twoLPFs, and one diplexer. The antenna switch is formed from two diodes,two inductors and five capacitors. The diplexer is located in an inletfrom an antenna and it is a filter element with three ports forseparating two frequency spectrums of a dual band. The diplexer isformed from a HPF that passes the high frequency side and an LPF thatpasses the low frequency side. The LPF of the diplexer is formed fromtwo Ls (inductors) and three Cs (capacitors) and the HPF of the diplexeris formed from one L (inductor) and three Cs (capacitors).

For example, a plurality of capacitors obtained in Embodiment Mode 1 aremounted as a first layer including a functional circuit 101; a CPU usinga CMOS circuit obtained in Embodiment Mode 2 and a memory formed inEmbodiment Mode 3 is mounted as a second layer including a functionalcircuit 102; an antenna switch comprising a diode, an inductor and acapacitor obtained in Embodiment Modes 1 and 2 is mounted as a thirdlayer including a functional circuit 103; an antenna pattern is mountedas a fourth layer including a functional circuit 104; a plurality ofinductors obtained in Embodiment Mode 1 are mounted as a fifth layerincluding a functional circuit 105; a plurality of resistors obtained inEmbodiment Mode 5 are mounted as a sixth layer including a functionalcircuit 106; and each of them are connected appropriately by a wiringpattern 114 and the front end portion and the CPU are formed on thecircuit board 100 by combining the elements. The CPU controls the wholedevice.

Noise can be reduced by integrating various circuits like this.

Further, it is possible to form and mount various types of filtercircuits, a processing circuit for audio or video, various types ofinterface circuits and the like, in a similar way, without using asemiconductor substrate.

For example, a VCO (voltage controlled oscillator) which determines anoscillator condition can be formed by appropriately arranging a TFT asan oscillator, a varicap diode for varying voltage and a capacitor, aninductor, and a resistor in the periphery thereof, in the semiconductorsubstrate 100.

A high frequency circuit is exemplified here, but it is possible tofurther integrate, and mount a flash memory, a solar battery, a sensorelement, a light-emitting element and the like on the same circuitboard, in addition to the high frequency circuit.

A top face of the circuit board may be covered with mould resin or aprotective case. Further, a lead (a pin) may be arranged from the side.

An example of mounting on the circuit board is shown herein, but it isnot limited particularly. It is also possible to mount on a glasssubstrate, a plastic film or the like for which a display portion, awiring or a circuit is provided.

FIG. 9 (B) is a cross-sectional view taken along a dotted line A-A′ inFIG. 9(A). In FIG. 9 (B), the first layer having a functional circuit101 is electrically connected to the wiring pattern 114 and mounted by asolder 107. Moreover, the second layer including a functional circuit102 is fixed with an adhesive agent 108 including electrical conductiveparticles, and an electrode 109 provided for the second layer includinga functional circuit 102 is connected to the wiring pattern 114 withelectrical conductive particles. In addition, the third layer includinga functional circuit 103 is fixed with an adhesive agent 111 a, and isconnected to the wiring pattern 114 with a wire 112 by a wire bondingmethod. The fourth layer including a functional circuit 104 is fixed tothe third layer including a functional circuit 103 with an adhesiveagent 111 b, and is connected to the wiring pattern 114 with a wire 112formed by a wire bonding method. The fifth layer including a functionalcircuit 105 is connected to the wiring pattern 114 with a bump 113formed by a transfer bump method. Note that the wiring pattern 114 isconnected to a solder ball 115 that is to be an external terminalthrough a through-hole that is formed in the circuit board 100. Thereare an ultrasonic solder bump forming method, a solder bump formingmethod by electroless plating, a solder bump forming method by atransfer method and the like as a method for forming the solder ball115.

An example of mounting by various mounting methods is shown in FIG. 9,but one mounting method may be standardized or the methods may beselected appropriately.

Embodiment Mode 9

Herein, an example in which a spiral inductor and a TFT are laminated isshown in FIG. 1.

Initially, a base insulating film 11 is formed on a first substrate 10.Then, a transmission line 12 is formed. The transmission line 12 is notlimited specifically, as long as it is a conductive material. Herein,the transmission line is wound up in spiral like about three times atregular intervals. The first substrate 10 may be a glass substrate, aplastic substrate, a ceramic substrate or a quartz substrate.

Then, an interlayer insulating film 13 and an extraction electrode 14are formed (FIG. 1 (A)). Note that FIG. 1(B) shows a top view.

A second substrate 30 in which an n-channel TFT 15 a and a p-channel TFT15 b are formed is bonded by an adhesive agent 16 b including electricalconductive particles 16 a (FIG. 1(C)). The extraction electrode 14 isconnected to the n-channel TFT 15 a or the p-channel TFT 15 b by theelectrical conductive particles 16 a. Note that a tungsten film 31 a anda silicon oxide film 32 are laminated over the first substrate 30 by asputtering method. A tungsten oxide film in an amorphous state is formedin forming the silicon oxide film. A heat treatment of 400° C. or moreis performed during the step of forming the TFTs 15 a and 15 b, a metaloxide film in an amorphous state is crystallized to obtain a metal oxidefilm 31 b having a crystal structure.

Then, the first substrate 30 for which the metal film 31 a is providedis separated by a physical means. It can be separated with relativelylittle force (for example, human hands, wind pressure of a gas blownfrom a nozzle, ultrasonic waves, or the like). Thus, a layer to beseparated formed over the silicon oxide layer 32 can be separated fromthe first substrate 30. FIG. 1(D) shows a state after the separation.

Then, after removing the tungsten oxide left on the surface, a heat sink18 is bonded by an adhesive agent 17. Specifically, when a highlyintegrated circuit such as a CPU circuit is formed by using a CMOScircuit, since heat easily generates, it is useful to bond the heat sinkfor radiating heat of an element. Note that the heat sink is notnecessarily provided, in the case of an integrated circuit to which heatgeneration does not matter.

Through the above-mentioned steps, a spiral inductor and a CMOS circuitcan be laminated and connected. Herein, the example of laminating thespiral inductor and the CMOS circuit is shown. However, it is possibleto laminate two or more layers to be separated including variouselements or wirings obtained in Embodiment Modes 1 to 7, and further toextract the electrodes or lead out the wirings to one another.

This embodiment mode can be freely combined with Embodiment Modes 1 to8.

The present invention having the above-mentioned structures is furtherdescribed in detail in Embodiments hereinafter.

Embodiment 1

A cellular phone having a GPS function is described as an example inthis embodiment with reference to FIG. 10.

In FIG. 10 (A), functional circuits such as an antenna, a receivercircuit, a transmitting circuit, and a GPS are formed, and further, aflash memory memorizing call-register, a camera controller, a controllerconnected to a display panel, a RAM and the like are provided. Inaddition, an amplifier for amplifying a signal from a microphone, anamplifier for amplifying a signal for outputting audio to a loudspeakerand the like are provided. Moreover, a CPU to be connected to them isprovided.

According to the present invention, a circuit in the portion surroundedby a dotted line in FIG. 10(A) can be manufactured and mounted on acircuit board without using a semiconductor substrate. A capacitor, aninductor, a resistor element, a SAW element and the like that are eachobtained according to any one of Embodiment Modes 1 to 7 are combinedappropriately to manufacture each functional circuit.

Although not shown here, a signal processor (DSP) is provided.

A functional block constituting a GPS is shown in FIG. 10 (B). The GPSfunction includes a system control, a Memory IF (memory interface), aPMU (path memory unit), a UART (receiving portion), an FCC, a DSP IFBuffer (a DSP (signal processor) interface buffer), an RFC IF (RadioFrequency Choke coil interface), an ADC IF (A-D converter interface),STI Logic (Set Interrupt Logic) and the like.

Note that the functional blocks that are different from one another maybe connected to one another by a glue logic (Glue Logic) that operatesthe functional circuit block in parallel coordination.

Some or all of circuits in the portion surrounded by the dotted line canbe mounted on a display panel board.

An example of a cellular phone is shown here, but the present inventioncan be applied to other personal digital assistants, card (a telephonecard, an ID card, a card having a circuit, or a card having asemiconductor element), a video camera, a digital camera, a goggle typedisplay, a navigation device typified by a car navigation, a DVD playeror an electronic game machine. As a result, further weight saving,thinning, cost reduction, and mounting area reduction can be realized.

This embodiment can be freely combined with Embodiment Modes 1 to 9.

Embodiment 2

In FIG. 13 (A), reference numeral 1001 denotes a central processing unit(also, referred to as a CPU), 1002 denotes a control unit, 1003 denotesan operation part, 1004 denotes a memory unit (referred to as a memory),1005 denotes an input unit, and 1006 denotes an output unit (such as adisplay portion).

The central processing unit 1001 includes the control unit 1002 and thearithmetic unit 1003. The operation part 1003 comprises an arithmeticlogic unit (ALU) for performing arithmetic operations such as additionand subtraction, or logical operations such as AND, OR, and NOT, variousregisters for temporarily storing data or results of the operations, acounter for counting the number of 1 that are inputted, and the like.Circuits constituting the operation part 1003, such as an AND circuit,an OR circuit, a NOT circuit, a buffer circuit, a resistor circuit, canbe formed from TFTs. For the sake of obtaining a high field effectmobility, a semiconductor film that has been crystallized by laser lightof a continuous wave laser may be formed as an active layer of the TFT.

A tungsten film and a silicon oxide film are formed over a substrate bya sputtering method, then a base insulating film (a silicon oxide film,a silicon nitride film, or a silicon oxynitride film) is formedthereover, and then an amorphous silicon film is formed thereover. In alater step, separation is performed by using a tungsten oxide layerformed at the interface between the tungsten film and the silicon oxidefilm.

Crystallization methods are given as follows: a method of adding a metalelement serving as a catalyst to an amorphous silicon film, heating itto obtain a polysilicon film and obtaining a polysilicon film byirradiating with laser light of a pulsed laser; a method of emittinglaser light of a continuous wave laser on an amorphous silicon film toobtain a polysilicon film; a method of heating an amorphous silicon filmto obtain a polysilicon film and irradiating it with laser light of acontinuous wave laser to obtain a polysilicon film; or a method ofadding a metal element serving as a catalyst to an amorphous siliconfilm, heating it to obtain a polysilicon film and obtaining apolysilicon film by irradiating with laser light of a continuous wavelaser. In the case of using continuous wave laser light, the directionof a channel length of the TFT constituting the operation part 1003, thecontrol unit 1002 or the memory unit 1004 is preferably the same as ascanning direction of the laser beam.

The control unit 1002 has a function of executing an instruction storedin the memory unit 1004 and controlling the whole operation. The controlunit 1002 includes a program counter, an instruction register, and acontrol signal generating unit. The control unit 1002 can be also formedfrom TFTs and a crystallized semiconductor film may be manufactured asan active layer of the TFT.

The memory unit 1004 is a place for storing data and instructions forperforming operations. Data or programs that are often executed in theCPU are stored therein. The memory unit 1004 includes a main memory, anaddress register, and a data register. A cache memory may be used inaddition to the main memory. These memories may be formed from a SRAM, aDRAM, a flash memory, or the like. When the memory unit 1004 is formedfrom a TFT, a crystallized semiconductor film can be manufactured asactive layers of the TFT.

The input unit 1005 is a device for receiving data or program fromoutside. The output unit 1006 is a device for displaying results,typically, a display device.

A layer to be separated including the thus obtained CPU (including aterminal electrode and a leading wiring) is separated from the substrateand transferred to a plastic substrate.

In addition, not only the CPU but also various circuits including acurrent circuit, a display portion, and a driver circuit unit can beformed together. For example, a card having a noncontact type thin filmintegrated circuit, a body-worn computer and the like can bemanufactured.

FIG. 13(B) is a view of a card having a noncontact type thin filmintegrated circuit.

FIG. 13(B) is a top view showing the specific structure of thenoncontact type thin film integrated circuit. It has a display portion,an antenna 1031, a current circuit 1032, an integrated circuit unit 1035including a CPU 1033, a memory 1034, or the like, in which the antennais connected to an IC via the current circuit. The current circuit 1032may have at least a diode and a capacitor, and has a function forconverting the alternate current frequency wave received by the antennainto the direct current. The antenna 1031 can be formed in the same stepfor forming the integrated circuit.

A feature of a noncontact type IC is that it is supplied with anelectric power by an electromagnetic induction action (electromagneticinduction type) of a coiled antenna, a mutual induction action(electromagnetic coupling type), or a induction action by staticelectricity (electrostatic coupling type). The height of the receivedfrequency can be selected by controlling the number of coil windings.

The frequency of remote type is micro wave; vicinity and proximity,13.56 MHz; and close type, 4.91 MHz, generally. The number of coilwindings can be reduced by increasing frequency and shorteningwavelengths.

Compared with a contact type thin film integrated circuit, a noncontacttype thin film integrated circuit is unbreakable, highly durable, andfree from an error by static electricity or the like, since thenoncontact type thin film integrated circuit carries out power sourcesupply and information communication without contacting with areader/writer. The structure of the reader/writer itself is notcomplicated. Further, the noncontact type one is easy to use, since whatis necessary is to hold up the thin film integrated circuit to thereader/writer.

A noncontact type integrated circuit comprises a CPU, a memory, an I/Oport, and a coprocessor, and exchanges data via a path. Further, the IChas an RF (radio frequency) interface and a noncontact interface. Thereader/writer as a reading unit comprises a noncontact interface and aninterface circuit, and carries out information communication andexchange between each the noncontact interface by communications or anelectronic wave by holding up the IC to the reader/writer. Then,information communication and exchange is carried out by the interfacecircuit of the reader/writer with a host computer. Naturally, the hostcomputer may have a reader/writer unit.

FIG. 13(C) is an external view of a plastic card corresponding to FIG.13 (B). In FIG. 13(C), 1010 is a main body of a plastic card, 1011 is adisplay portion, 1012 is a memory unit, and 1013 is a CPU. In case ofusing it as an identification card, a lightweight and flexible card canbe obtained. Further, when the identification card becomes useless, itis possible to easily cut and break it into parts and to makeinformation in the memory unit unreadable completely and to preventforge and copy the card.

If required, a battery (a sheet like battery or a solar battery) fordriving a display portion or the like may be provided. A sheet likebattery, a solar battery or the like can be manufactured by separatingand transferring. The sheet-like battery is provided with plural solidpower generation cells comprising power generation factors in which apositive electrode active material, a solid electrolyte, a negativeelectrode active material are stacked in layers on a sheet. For thepositive electrode active material, the solid electrolyte and thenegative electrode active material, carbon system materials such as alithium cobalt oxide, a lithium nickel oxide, a lithium manganese oxide,a lithium vanadium oxide, a lithium titanium oxide, a metallic lithium,a lithium alloy, a manganese dioxide, graphite and coke, a niobiumpentoxide, a lithium transition metal compound nitride, a PEO(polyoxyethylene oxide), lithium phosphate etc., can be used. Further,an electronic conduction material such as carbon, or acetylene black oran additional material such as a polymeric binder may be mixed intothese materials.

The device shown in FIG. 13 (D) is an example of a personal digitalassistant having a plurality of liquid crystal display portions.

The device shown in FIG. 13 (D) can be folded by a fold moving part1023, and can have a business card size. The plurality of displayportions can be protected as well as miniaturization of the device byfolding it. A plastic 1020 is used for the main body and thus, it islight. The device has a left side display portion 1021 and a right sidedisplay portion 1022. The display portion may be provided with animaging unit (solid imaging element such as CCD camera) 1024 on thebackside. Data imaged by the imaging unit 1024 can be directly displayedon the left side display portion 1021 or the right side display portion1022 via a camera interface portion or the like. The left side displayportion 1021 and the right side display portion 1022 are each preferablya touch-panel so that a user can perform various input operations withit.

The main body of the plastic 1020 is provided with a main controlsection including a CPU for overall-controlling a display portion andeach part of the main body etc., a memory unit, a display portion drivercircuit, a power supply circuit portion, an operation input controlpart, a modulator-demodulator circuit portion, a transmitter-receivercircuit portion, an antenna or the like. A part or all of them can beformed on a plastic by the present invention.

For example, when data is transmitted, text data input by an operationkey (not shown in the figure) or a touch panel operation are transmittedinto a main control section through an operation input control part. Inthe main control section, spectrum diffusion process is performed on thetext data in the modulator-demodulator circuit portion, and after adigital-to-analog conversion processing and a frequency conversionprocessing are performed in the transmitter-receiver circuit portion,and the text data is transmitted to a base station through the antenna.In addition, when data is received, a spectrum reverse diffusionprocessing is performed on a signal received through the antenna fromthe base station in the modulator-demodulator circuit portion, and afterthe original text data is recovered, it is displayed as data in thedisplay portion through the display portion driver circuit.

Note that the device shown in FIG. 13 (D) may function as an ultrasmallcomputer. Although not illustrated, a battery (a sheet-like battery or asolar battery) is also provided in the main body of the plastic 1020,too. A sheet like battery, a solar battery or the like can bemanufactured by separating and transferring. Moreover, a bluetoothcommunications part may be provided in the main body of the plastic1020.

1. A method of manufacturing a semiconductor device comprising the stepsof: forming a first metal oxide film over a first substrate; forming afirst functional circuit comprising a thin film transistor over thefirst metal oxide film; peeling the first functional circuit from thefirst substrate at the first metal oxide film; mounting the peeled firstfunctional circuit over the circuit board with a first adhesive agent;forming a second metal oxide film over a second substrate; forming asecond functional circuit comprising a passive element over the secondmetal oxide film; peeling the second functional circuit from the secondsubstrate at the second metal oxide film; and mounting the peeled secondfunctional circuit over the circuit board with a second adhesive agent.2. A method according to claim 1, wherein the circuit board is a ceramicboard or a resin substrate.
 3. A method according to claim 1, whereinthe passive element is at least one of a capacitor, an inductor and aresistor element.
 4. A method according to claim 1, further comprising astep of forming a heat sink over the first functional circuit.
 5. Amethod according to claim 1, further comprising a step of forming anantenna pattern over the second functional circuit.
 6. A methodaccording to claim 1, wherein the first functional circuit comprises aCMOS circuit.
 7. A method according to claim 1, wherein the secondfunctional circuit is at least one of a low pass filter, a bandpassfilter, a diplexer, a coupler and a balun.